About windings and fittings --
Windings - The decision by the bow maker to use one material over another on the winding depends on where the balance is and what material will benefit the balance of the bow best. Windings typically used are imitation whalebone, silver tinsel (on silver bows), or nickel/silver.
Bows described as 'nickel' or 'nickel/silver' are wound with either nickle/silver or whalebone (imitation). The frog and button metal will be nickel/silver. Nickel/silver is an alloy containing no actual silver, but with a silvery appearance.
Bows described as 'silver' models may have windings of silver tinsel (silver on silk thread), whalebone (imitation), or silver. The frog and button metal will be silver.
Silver bows also use a higher grade of stick material, whether that be wood or carbon, and are considered a better bow not just because of the fittings, but because of the stick.